1. Field of the Invention
The present invention relates to a liquid crystal display device packaged or mounted on a variety of electric appliances such as a portable telephone terminal, and more particularly to a liquid crystal display device capable of assuring lightproofing of a bare-chip type liquid crystal driver.
2. Description of the Related Art
Conventionally, in a liquid crystal display device to be mounted in a variety of electric appliances, a bare chip constituting a liquid crystal driver therefor is housed in a package so that the light reaching the bare chip is shielded.
With recent progress of low-profiling and down-sizing of a variety of electric appliances, a system of mounting or packaging the liquid crystal driver has been shifted from surface mounting, in which a chip is completely light-shielded by a molding material, to COB (Chip on Board), TCP (Tape Carrier Package) and COG (Chip on Glass). In these systems, in which a bare chip of the liquid crystal driver is mounted on a circuit board, the bare chip is susceptible to influence by light.
However, in the liquid crystal display device as described above, in which display is generally made by reflection of light, the bare chip which is not housed in a package is susceptible to influence by reflected light for display. Then, because of the reflected light, the liquid crystal driver gives rise to photoelectric effects leading to erroneous display. In addition, mounting the bare chip in a package hinders low-profiling and down-sizing of electric appliances.
The present invention intends to solve the above conventional problem and to provide a liquid crystal display device capable of surely shielding or absorbing light to reach a liquid crystal driver to prevent erroneous display due to the photoelectric effect of the liquid crystal driver.
Especially the object of the present invention is to prevent erroneous display due to the photoelectric effect of the liquid crystal driver in a very thin type of the liquid crystal display device.
In order to solve the above problem, the liquid crystal display device comprises a liquid crystal driver mounted on a bottom surface of an upper panel constituting a liquid crystal display panel and a light shielding film affixed to a top surface of the upper panel at an area which is opposite to a mounting position of the liquid crystal driver and serves to shield extraneous light incident on the liquid crystal driver.
In accordance with the present invention, without housing the bare chip type liquid crystal driver within a package, the light which reaches the liquid crystal driver is surely shielded or absorbed so that erroneous display due to the photoelectric effect can be prevented.
The first of the present invention is a liquid crystal display device which comprises:
a liquid crystal panel constituted by a first plate disposed on a displaying side, a second plate disposed on a reverse side of the displaying side, and liquid crystal cells held therebetween;
a liquid crystal driver electrically connected with the liquid crystal panel through a circuit pattern;
a light shielding material disposed on the displaying side of said liquid crystal driver so as to prevent an outer light from being incident to said liquid crystal driver. The shielding film surely shields the light to reach the liquid crystal driver.
Preferably the present invention further comprises a diffusion sheet located below the liquid crystal display panel and composed of a light diffusing area and a light absorbing area located on the outer periphery thereof, the light diffusing area serving to diffuse illumination light from a light source to the liquid crystal display panel, and the light absorbing area serving to absorb the extraneous light incident on the liquid crystal driver. The light absorbing area of the diffusing sheet absorbs the extraneous light incident on the liquid crystal driver so that the light to reach the liquid crystal driver is surely shielded.
Preferably the present invention is characterized in that the light which reflects from said diffusion sheet to reach the liquid crystal driver is shielded by resin applied for protecting a transparent electrode of the liquid crystal display panel. The resin shields the light reflected by the diffusion sheet to reach the liquid crystal driver.
Preferably the invention is characterized in that the light shielding film, light absorbing area of the diffusion sheet and resin are colored in black. This configuration improves the shielding effect of light to reach the liquid crystal driver.